Drinking Water Quality

Drinking Water Quality

 Livermore Municipal Water receives its wholesale water supply from the Zone 7 Water Agency, which treats water from the State Water Project in the Sacramento-San Joaquin Delta and groundwater wells in Pleasanton. The water that is supplied by Zone 7 Water Agency meets or is better than all federal and state drinking water regulations. Zone 7 Water Agency and Livermore Municipal Water are required to closely monitor all water supplies and provide the results to customers in Annual Water Quality Reports. 

What does Livermore Municipal Water do to ensure water quality?

Livermore Municipal Water conducts weekly water quality tests at nine sites throughout the water distribution system to ensure the safety of the water being delivered to its customers. If test results show that chloramine residual levels are lower than required, the system is flushed as a precaution.


Chloramine is a disinfectant that helps to protect water quality as it moves through pipelines to customers. It is important to water quality because over time, small particles of rust and sediment can accumulate inside water main pipes, which could lead to bacteria growth.

Flushing water lines brings in “new” water to the system at a high velocity. Along with raising the water’s chloramine levels, flushing water lines also removes residue and sediment from the water main pipe and helps reduces taste and odor problems.

Why does the taste of my water change from time to time?

The minerals in a water supply affect how water tastes, just as different brands of bottled water taste differently. Livermore Municipal Water receives its water from Zone 7 Water Agency. Zone 7 Water Agency treats water from the Sacramento-San Joaquin Delta and groundwater wells in Pleasanton. As part of managing these water sources, Zone 7 will vary the mixture of Delta water and groundwater delivered to the Tri-Valley. Livermore Municipal Water mostly receives treated Delta water, though on occasion it will receive more groundwater. This variation in the mix of Delta water and groundwater may result in changes in the water’s taste.

Why does my water smell?

To determine the cause of the smell, let your water run for 30 seconds before rinsing and filling a glass. Characterize the smell.
  • No smell: The smell is probably coming from bacteria in the P-trap under the drain. Other smells could be from home water treatment systems — check the system, e.g. filters.
  • Chlorine/chemical smell: Oftentimes, the smell detected is the result of chlorine used to disinfect the water supply. If the smell is particularly bothersome, let the water stand in an open container until the chlorine dissipates.
  • Earthy/musty smell: Algal blooms in the Sacramento-San Joaquin Delta can produce compounds that create an earthy/musty smell and taste in drinking water. These compounds are not harmful to human health but if the smell or taste is bothersome, add a slice of lemon or chill the water. Learn more on Zone 7 Water Agency’s website.
  • Foul smell: Foul odors often come from drains or garbage disposals. To get rid of the odor, fill the sink with hot water, add an ounce of household bleach, and allow the water to drain slowly.

Does my water contain fluoride?

Water supplied by Livermore Municipal Water does not contain fluoride.

Who can I contact for more information on my water quality?

Livermore Municipal Water is happy to answer any customer questions. Please call (925) 960-8100 Monday – Friday, 8:00 a.m. – 4:00 p.m. If it is an emergency, please use our emergency line (925) 960-8160 on weekends, after hours, or on holidays.